In automatic machinery for sewing buttons in place, difficulties arise in ensuring that the buttons are the right way up and arranged with the thread holes aligned with the sewing needle. Moreover, the machines presently provided for this purpose include rapidly moving parts which, being exposed for the transfer of correctly oriented buttons to a sewing machine, present a hazard to operators.
Buttons are normally provided with two or more holes for thread by which the buttons are to be sewn in place and so it is necessary to orientate buttons fed to an automatic sewing machine so that these holes are correctly orientated for receiving the needle of the automatic sewing machine.
In one form of apparatus provided for this purpose, buttons are moved along a track and resiliently loaded clamping means are provided along one side of this track so as to provide frictional engagement with the edges of the buttons so that the buttons are caused to roll along this side of the track and thus caused to rotate. A button support disposed below the track and moved along the track below a button moving on the track is provided with pins for insertion into the holes formed in the button and, as soon as the button rotates to an orientation in which the holes are aligned with the pins, the button support is raised under the influence of resilient loading means so that the pins are inserted into the holes and the button is correctly orientated for transfer to the sewing station. During further movement of the button along the track, rolling movement is prevented.
Unfortunately, this form of apparatus is unsuitable for use with non-circular buttons and is even unsuitable for circular buttons in which the edges of the rim engaged by the resiliently loaded clamping means are irregular in shape and therefore unsuitable for uniform frictional engagement with the clamping means.
One known form of apparatus which has been devised to meet this deficiency comprises an upwardly biased button support; pins projecting upwardly from the button support, for insertion in the holes in a button; positioning means for positioning a button above the button support; and rotary frictional drive means for effecting relative rotation between a button on the positioning means and the button support until the holes in the button are aligned with the buttons on the button support to thereby permit the button support to raise and the pins to enter the holes.
In this known apparatus, the button support is non-rotational and the rotary frictional drive means comprise a rotatable pad which is movable into and out of frictional engagement with a button on the positioning means. As soon as the pins on the button support penetrate the holes in the button, the button is held correctly orientated for transfer to the sewing machine and so the frictional resistance to relative movement between the pad and the button is overcome.
Although this form of apparatus avoids the deficiencies of earlier designs, difficulty is encountered in placing each successive button on the positioning means centrally on the axis of rotation of the rotatable pad. Clearly, this deficiency is most acute when handling non-circular buttons and it is an object of the invention to overcome this deficiency.
In order to transfer the correctly orientated buttons from the orientating apparatus to the sewing machine, where they are clamped in position so that the needle of the sewing machine can penetrate the holes in each button, it is known to provide a button transfer apparatus comprising an upwardly biased radius arm having a free end and support means permitting rotary oscillation about a vertical axis; a button support mounted at the free end of the radius arm and provided with upwardly extending pins for insertion into the holes in buttons; rotary drive means for effecting rotary oscillation of the radius arm about the vertical axis between first and second angular positions in which the button support is able to engage a correctly orientated button and in which a button engaged by the button support can be clamped in a sewing machine; and rectilinear drive means for lowering the radius arm from a first level to a second level when the radius arm is in its second angular position and for enabling the radius arm to rise from the second level to the first level for insertion of the pins on the button support in the holes in buttons when the radius arm is in its first angular position. However, as the radius arm of this transfer apparatus, at least, is exposed and subjected to rapid movement, there is a danger of an operator coming into contact with this radius arm and it is an object of the invention to overcome this safety hazard.
Buttons are also commonly formed with a convex under surface and the under surface of the periphery of the button is relieved more than the upper surface adjacent the periphery. It is therefore important that these buttons are correctly arranged with their upper surfaces uppermost.
Apparatus is therefore provided for achieving this and comprises a track along which buttons are able to move, in single file, and guide means which permit buttons with their upper surfaces uppermost to proceed along the track and which enable upside-down buttons, with their under surfaces upper most, to be deflected laterally of the track.
In one known form of such apparatus, the guide means are provided at a narrowed portion of the track and comprise a series of laterally projecting fingers which are spaced apart, along the length of the track, by a distance of less than the diameter of the buttons to be sorted. Buttons with their upper surfaces uppermost are therefore adequately supported as they progress along the track. However, these upper surfaces are formed with a central concavity so that when the buttons are upside-down, with their under surfaces uppermost, the central concavities pass across the ends of the laterally projecting fingers so that these fingers are unable to support the upside-down buttons which therefore topple sideways, off the track.
However, this form of apparatus can only be utilised with buttons formed with central concavities in their upper surfaces and it is an object of the present invention to overcome this deficiency.